Contrary to Cameron's Munich (slightly unfortunate choice of venue) speech - I'd have to suggest that multiculturalism is actually easier in practice than it looks on paper.
Sometimes it's difficult to take on board that the Tory-boy lives in the same city as I do: Any time spent in an inner city would reveal that multiculturalism is simply the default setting for ordinary people going about the daily business of making lives for themselves and their families. Sometimes there are tensions, often there are misunderstandings, but on street level it works because it has to.
Just on my own street Polish shops sit cheek by jowl with Kurdish shops. My daughters' anglo-french-jewish-hungarian heritage is probably the least exotic and most ethnically homogeneous of their circle of friends. Nobody I know even notices or cares.
So what is the alternative Cameron proposes - monoculturalism ?
He hankers after a state-defined set of national values taught in schools and measured by a citizenship test. Examples of country's with such imposed artificial constructs being the USA and France - both far less integrated societies in practice than the UK and with ethnically defined ghettos in their cities the like of which simply don't exist over here.
Or maybe he just wants to sentimentalise some non-diverse national heartland - like the parts of this country that are still demographically homogenous. I grew up in one of these - the London suburbs of thirty years ago. 'British' values - specifically the values of the affluent working class and the lower middle class - ruled the roost without challenge - mowed lawns, washed cars, pubs and Sunday roasts. It was fucking tedious and depressing...fortunately it is dying a natural death.